1. Field of Invention
This invention relates to a fuel filling port device used for filling internal fuel tanks on pleasure boats and other marine vessels. The device employs a controlled temporary storage chamber that contains the backed up overflowed fuel that occurs during fueling, for a period of time necessary to prevent spilling. Immediately thereafter the device automatically empties the fuel from said storage chamber back into the fuel tank, preventing spilling and subsequent polluting of our waterways.
2. Description of Prior Art
Internal fuel tanks on pleasure boats and other marine vessels have an air vent which allows air and fumes to escape into the atmosphere while fuel is being pumped into the fuel fill port and is displacing the air from within the fuel tank during the fueling operation. The air vent tube is approximately 0.5" diameter, while the fill port tube is approximately 1.5" diameter. As the fuel tank is being filled the boat or vessel tends to rock and list continuously, causing the liquid fuel to slosh back and forth continuously. As this occurs the liquid fuel reaches a level that tops the tank filling inlet, causing momentary false fills, forcing the incoming fuel to back up through the fill hose and spill out of the prior art fill port, spilling fuel both onto the boat and into the waterway. This spilling continues periodically during fueling, depending on the frequency and degree of the marine elements such as, wind, current, wakes from passing boats, and the very movement of the passengers on board. Finally, as the fuel tank actually becomes full, one final spill occurs, which combined with the prior spillage, causes substantial pollution of the surrounding waterway.
The spilling of gasoline fuel in addition to polluting, poses a further potential danger due to its flammability.
Presently, the most common prior art design of fuel filling ports on boats are flanged tubes that fit through and are mounted to the deck or gunwale of the boat above the fuel tank, and are attached below deck by a clamp to a hose that feeds the fuel into the fuel tank, which is commonly found below deck. The flange that enables attachment of the prior art fill tube to the deck or gunwale, is purposely designed with a half inch high circular containment wall on the outer perimeter of the flange with an opening in the wall of approximately three quarters of an inch facing toward the waterway. This is designed so, that when the prior art port fill tube becomes full and a fuel spill occurs the fuel is prevented from spilling into the boat and is directed to spill toward the waterway and away from the boat's interior. Additionally, most prior art fill ports have tethered caps that are attached from the underside of the cap to an attachment within the fill port tube opening, this tether is usually small chain links of sorts that tend to kink during the turning of the cap to unscrew and remove the cap, this kinking of the chain links causes an obstuction and subsequent difficulty of inserting the filling nozzle.
The present method using the prior art port tube to fill the internal fuel tank as found on most pleasure boats and other marine vessels is as follows:
a) The port fill cap is unscrewed, exposing the port fill tube opening, the fill nozzle attached to the fuel fill hose leading from the main pump at the fuel dock is inserted into the port fill tube opening. The trigger on the fill nozzle is then squeezed allowing fuel to flow through the fill port tube inlet, down the hose into the vessel's internal fuel tank. PA1 b) As the fuel filling process takes place, the floating vessel tends to list and rock in many directions caused by various marine elements including: wind, wake from other vessels, tidal currents, and movement from passengers on board. This rocking motion causes the boat to tip or list in various directions, causing the fuel to slosh back and forth and from side to side within the fuel tank, causing the fuel within the tank to momentarily rise up in the interior side of the tank where the filling is taking place, this action causes a momentary false fill and backs the fuel up the fill tube and causes spills out of the filling port tube, causing fuel spills even before the tank is full. PA1 c) As the fuel enters the fuel tank, the existing air within the fuel tank becomes displaced by the incoming fuel and this air is forced to escape via the through hull air vent. As a result of the above mentioned marine conditions however, the 0.5" diameter hose leading to the 0.5" diameter air vent cannot vent as rapidly as the incoming fuel being pressure fed through a 1.5" intake hose. This also results in a "false fill", causing a backup spill at the fill port. PA1 d) The above conditions may take place several times during the fueling process, depending on the frequency of motion caused by the said marine elements and the fuel tank configuration and capacity, eventually resulting in multiple spills during one fill. Studies investigating spillage, as well as observations of the fueling procedure at various busy fuel docks yielded the following results: the fuel dock attendants report that 80 out of 100 boats that are fueled will have spills of several ounces overflowing out of the filling port and into the waterway. For this reason most fuel docks keep cases of a soap product called "Liquid Dawn" available which, when applied directly onto a waterway affected by fuel spillage, helps to camouflage the pollution by dispersing the sheen caused by the fuel spill. The boat owners that were interviewed reported that they spill fuel as well most of the time during fueling. PA1 To prevent pollution by containing the back up of fuel in a containment chamber within the fill port. PA1 To allow the enforcement and monitoring of this type of pollution to become manageable. PA1 To allow ease of installation and replacement of prior art fuel fill port tube. PA1 To provide a fuel fill port device economically fabricated of material that will not be adversely affected by gasoline, diesel fuel and the marine environment.
The U.S. Department of Environmental Protection estimates there are 12 million marine engines in our nations waterways. If only three quarters of them are pleasure boats with internal fuel tanks, with an average of one fueling per week during a six month boating season, during which 75% of each fueling spills on average two ounces of either gasoline or diesel fuel, a tremendous pollution problem results. The above conservative figures, yield the following calculations: 105,468 gallons of gasoline and/or diesel fuel spill per fueling or per week nationwide resulting in a total of 2,531,250 gallons spilling into our waterways per six month boating season. This problem grows with every new boat purchased each year. While there are laws in place to prevent this pollution, they are not being enforced due to a lack of monitoring manpower.
This invention corrects the aforementioned problems by preventing this particular overflow spill pollution from taking place, during fueling.